The present invention relates to electric components and is intended for application in the constructive development of a triggerable switching spark gap, in the case of which a galvanically triggerable electrode is configured concentrically inside an electrode of the main discharge gap. These types of components are used, inter alia, as controllable high-voltage switches in ignition devices. The high-voltage switch thereby transfers the energy stored in a capacitor quickly and with low-loss to a load, for example, to an ohmic resistor, which converts electrical energy into thermal energy, or to the primary winding of an ignition coil. This energy transfer must take place with low loss and quickly, that is, in particular, with a high rate of rise of the current and voltage pulses.
A known triggerable switching spark gap essentially comprises a gas-discharge space and a trigger electrode; the gas-discharge space is thereby defined by a cylindrical insulator, for example, a ceramic or glass tube, and by a first and a second main electrode, which are configured at the ends of the insulator and are connected in a vacuum-tight manner to this insulator. The main electrodes each have a flat discharge surface; the two discharge surfaces stand axially opposite each other. A cylindrical trigger electrode is arranged inside the first main electrode and is insulated from this electrode; thus this cylindrical trigger electrode is situated in the center of a circular opening of the first main electrode. The discharge surface of the trigger electrode is arranged to be flush with the discharge surface of the first main electrode; a cylindrical insulating body with which the trigger electrode is insulated from the first main electrode is arranged in the same way (see the brochure "EEV Spark Gaps" by the firm EEV).
If during the operation of such a known switching spark gap, a high-frequency, high-voltage pulse is applied to the trigger electrode, then the ignition of the discharge gap between the two main electrodes is introduced through a predischarge. The period of time from the ignition of the predischarge until the actual switching operation is defined as delay time or as ignition delay time. This amounts in the case of customary switching spark gaps to about 0.7 to 2 .mu.s, at a voltage to be switched of 2 kV and at a natural breakdown voltage of about 3 kV. The gate-controlled rise time of the main discharge gap amounts to about 0.2 .mu.s.